When logging into a Costco account, what action is often required?

When logging into a Costco account, the action of signing on and off is vital for maintaining security and access control. Signing on ensures that authorized users can access their account information, including order history, membership details, and personal preferences. This step is essential in verifying the identity of the account holder, which helps to protect sensitive data and ensures that only the account owner can make changes or view information associated with the account.

While other actions like entering a membership number, resetting a password, or choosing a store location may be relevant in specific contexts, they are not routinely required each time a user logs in. Signing on and off is the fundamental action that initiates the login process, so it is appropriate to focus on this aspect as the correct choice in the context of logging into a Costco account.